1. Field of the Invention
This invention relates to a process for making an elastic stretch woven fabric and the product made thereby. More particularly, the invention concerns an improvement in such a process and product. The improvement involves the fabric being woven with a combination yarn that comprises an elastomeric yarn and a companion yarn of partially oriented non-elastomeric polymer.
2. Description of the Prior Art
Processes are known for making stretch-woven fabrics. For example, Lycra.RTM. spandex Fiber Bulletin L-94, "Producing stretch-woven fabrics from core-spun yarns containing LYCRA.RTM. spandex fiber," E. I. du Pont de Nemours & Co. (April 1980) describes the fabric design and construction, weaving, heat-setting and dyeing and finishing of filling-stretch, warp-stretch and two-way stretch woven fabrics. A core-spun yarn is a combination yarn that is produced by spinning a sheath of "hard" fibers (i.e., conventionally drawn, oriented non-elastomeric fibers, filaments or strands) around a core of elastomeric strand while the elastomeric strand (e.g., spandex) is under tension and elongated to several times its relaxed length. Subsequent release of the tension and contraction of the elastomeric core strand yields a stretchable combination yarn. Other processes for making stretchable combination yarns are known wherein elastomeric strand is combined with hard fibers, for example, by covering, air-jet entangling, plaiting and the like. However, woven stretch fabrics made with such combination yarns, typically have much smaller dimensions than the length and width of the loom on which the fabrics were woven.
Greenwald et al, U.S. Pat. No. 3,357,076, discloses processes in which woven stretch fabrics are made with another kind of elastic combination yarn. The combination yarn of Greenwald et al is produced by wrapping undrawn synthetic filamentary material around a non-extended, non-heat set, elastomeric core strand. The woven fabric is stretched to draw the undrawn filamentary wrapping of the combination yarn. Then, the stretched fabric is at least partially relaxed and heat set in the partially relaxed state. Stretch fabrics made by the process of Greenwald et al are stated to exhibit a variety of surface effects and a stretch in the range of 10% to 215%.
The one example of Greenwald et al describes a fabric woven to a 45-inch (114-cm) width, stretched at 220.degree. F. (104.degree. C.) and subsequently treated in three different ways, as follows. In part (1) of the Example, the woven fabric, after having been stretched to a 55-inch (140-cm) width, was relaxed to a 43-inch (109-cm) width and then heat set at 380.degree. F. (193.degree. C.) in the relaxed condition. The resultant fabric was described as a terry-face fabric having a potential stretch of 40%. In part (2) of the Example, the fabric after having been stretched to a 110-inch (279-cm) width, was relaxed to a 48-inch (122-cm) width and then heat set at 380.degree. F. (193.degree. C.) in the relaxed condition to yield a terry-face fabric having a 215% potential stretch. In part (3) of the Example, after having been stretched to a 110-inch (279-cm) width, the woven fabric was not relaxed but was heat set at 380.degree. F. (193.degree. C.) while fully stretched at the 110-inch (279-cm) width to yield a fabric having a knit-deknit appearance and a potential stretch of less than 10%.
The present inventor found that the fabrics of Greenwald et al have certain short-comings. When fabrics such as those produced in parts (1) and (2) of the Greenwald et al Example were further treated under typical finishing conditions of hot-wet dyeing and scouring at or near a temperature of 100.degree. C., the fabrics shrank considerably and lost most of their potential stretch. With regard to part (3) of the Greenwald et al Example, hot-wet finishing of the heat-set fabric did not improve the inadequate potential stretch of the fabric. In addition, the properties of undrawn fibers, which are required for the filamentary wrapping of the elastic combination yarn of the Greenwald et al process, change significantly when stored for different lengths of time. Such changes in the undrawn fibers often make it very difficult to produce yarns and fabrics with consistent properties and lead to inferior woven fabrics.
In view of the above-noted shortcomings of the known processes for making stretch woven fabrics, an object of the present invention is to provide an improved process and a stretch woven fabric therefrom that will overcome or ameliorate at least some of the shortcomings.